Countersink gauge



Aug. 20, 1940. A. A. SCHWARTZ COUNTERSINK GAUGE Filed June 4, 1940 INVENTOR Patented Aug. 20, 1940 UNITED STATES COUNTERSINK GAUGE Arthur A. Schwartz, Bufialo, N. Y., assigflor to Bel! Aircraft Corporaton, Buflcalo, N. 1.

Application June 4, 1940, Serial No. 338,765

6 Claims.

This invention relates to countersink depth gauges, and has for one of its objects the provision of an improved gauge of the character de scribed which is adapted to provide more accurate readings in connectionwith increased speed of use, and application to series of countersinks in-a common work piece; as in connection with preparation for multiple flush riveting manufacturing operations. Other objects and advantages of the invention Will appear in the specification. It is to be understdod that as used herein the term countersink is intended to mean any conica1 shaped opening or recess in a work piece.

In the drawing: V

Fig. 1 is a view partly inelevation and partly in vertical section of a gaugeof the invention mounted upon a work piece preparatory to movement thereon into gauging relation with respect to countersunk openings therein;.

Fig. 2 is a fragmentary vertical section, in a plane substantially at right angles to the plane of the sectionof Fig-1; on an enlarged scale, showing a portion of the gauge inoperative position relative to a countersunk opening in the work piece;

Fig. 3 is a horizontal section taken substantially along line IIIIII of Fig. 1; and

Fig. 4 is a bottom plan of the gauge.

.The gauge comprises .generally a tubular body member I0; an indicator l2 mounted at one end of the body member; a plunger l4 which is slidably mounted within the body l0 for actuaton of the indicator; and a countersink engaging bal] member l6 at theopposite end of. the body member for control of the pluznger l4. The bail member l6 is of highly polished metal or the like and of perfectly spherical form of' such diameter as to be adapted to rest upon thesloping face 18 of a countersunk portion ofthe work piece 20 as illustrated in Fig. 2. It is" preferred that the diameter of the ball 16 be Suchthat the contact between the ball l6 and the slopingsurface la is intermediate of the upper and lower limits'of the surface l8. The diameter of the ball meniber I6 will theref0re be regulated by the form and dimension of thecountersink to be gauged, and'for this purpose a set of differentlysized halls l6 will be'provided for use in connection with the gauge.

The bodymember Il) is generally boredto such diameter as to engage the plunger 14 in accurately fitted but longitudinally slidable relation therein, and is counterbored as at 22 t0 accommodate the ball member IS in such manner as to be free for substantial movements therewithin in all directlons radially of the vertical axis of the gangs.

The ballmember [6 is provided with an integral arm 24 adapted to extend through an opening in a side wa1l portion of the body member lu provided by atubular insert 26 mounted in screwthreaded relation therein. The insert 26 is 5' slotted as at 21 for engagement with a screw driver or similar tool during assembly or disassembly processes. The insert 26 and the ami 24 are so proportioned as to be adapted to prevent the bail [6 from moving totally out of en- 10 gagement with the body member l through the lower open end of the bore thereof whenever the gauge is lifted clear of the work piece. However, the arm 24 and the interior opening through the inSert 26 are so relatively proportioned as to allow the bail [6 to have full free movement in all (11: rectio-ns within the lower end of the body member short of complete withdrawal therefrom.

When the insert 26 is removed from the body member I!) the opening 50 provided in the body 20 member side wal1 is of such s'ize as to free'the arm 24 for complete withdrawal of the ball l6 through the lower end of the body member. Thus, the ball l6 may be readily withdraWn from the gauge for purpose of exchanging it with a 25 bail of different diameter; the tubular insert 26 being subsequently refitted in the body member after substitution of the ball members to prevent accidental disassembly of the device.

The plunger [4 is so dimensioned longitudinal- 30 ly as to bear against the upper portion of the bail le and to extend therefrom upwardly into abutting engagement with a stem 30 of the actuating mechanism of the indicator l2. The indicato-r l2 andthe actuating mechanism thereof are illus- 35 trated in Fig. 1 as being cf standard dial indicator form but it will be understood that in. lieu thereof any other form may be used, such as a suitable straight-line ne9dle type, as may be preferred. The indicator and actuating mechanism 40 thereof isrigidly mounted upon the gangs body Il! by having its shank portion 32 inset withina sp1it bushing 34 which in turn is rigidly mounted within a counterbored portion of the body l0 by means'of a set screw 36. The stem 30 of the in- 5 dicator actuating mechanism extends beyond the lower end ofthe shank 22 of the indicator mechanism and is provided with a hardenedend portion 38 for bearing against the upper end of the plunger l4. Consequently, the indicator meoha- 50 niSm may be conveniently removed from the device by retraction of the screw 36 which releases the bushing'34 and allows withdrawal of the indicator from the body member I0. The usua1 di adjusting scrw 31 is provided for manipulation 55 so as to conform the indicating mechanism to exchanges of difierent sized balls 16 in connection With the measurements of difierently diametered countersinks in the work piece.

The plunger I4 is reduced intermediateiy of its ends to provide a pair of opposed shoulders 40 for co-action With a set screw 42 penetrating an adjacent side wail portion of the body member l for 1imitng downward movement of the plunger within the body I 0 upon removal of the gauge from the work piece so as to prevent the operating elements of the gauge from becoming accidentally disassembled. The set screw 42 also functions to stop the upward movement of the plunger within the body member so as to pre- Vent accidental disassembly therefrom whcnevcr the indicator mechanism l2 may be removed.

The body member I!) is notched as at 28 to provide an opening through a side wa1l portion thereof so that a visual inspection et the ball contacting member l6 may be had at all times during use of the gauge;

To employ the gauge of the invention a bail member 16 of such diameter as to be adapted to reside within the countcrsink to be measured tangentially to the sloping surface portion l8 thereof is selected and mounted within the gauge. The dial of the indicator mechanism is then adjusted to conform to the selected hall size and to register zero whenever the gauge is set upon a plane surface as illustrated in Fig. 1. The gauge is then held upright in the position shown in Fig. 1 and siid over the surface of the work piece until the ball member 16 drops into one of the countersinks to be measured. The gauge is then shifted radially by the operator in all directions to insure freedom for the ball l6 to move into the full depth of the countersink; the loose fit between the ball 16 and the bore of the body member alloWng full centering of the ball in the countersink regardless of the exactitude of the position of the body of the gauge thereover. Consequently, as the operatorshifts the gauge radially about the location of the countersink the indicator i2 will reveal the position wherein the ball l6 is lowermost in the countersink, and the reading taken of the indicator under this condition will give the depth of the countersink.

The bottom face portion Il of the body member Il), as well as the operative contact portions Of the plunger M and the bail [6 are p1eferably formed cf hardened stee1 ground and lapped or otherwise reduced to'sm00th and accurate contoured form so that the measurements taken by the gauge will be precise.

A1though only one form of the invention has been shown anddescribed in detail, it W11] be apparent to those skilled in the art that the invention is not so limited bu}t that various changes may be made therein without departing from the spirit of the invention or the scope of the appended olaims;

I daim:

1. A countersink depth gauge comprising essentially a tubuiar body member adapted to rest at one of its ends against the Work piece, a spherical contact member mounted'within said body member at the work piece contacting end thereof and freely movable in all directions therewithin, an indicator mechanism.mounted upon the other end. of said body member and -h'aving an indicator actuating element extending into said body member} and a plunger slidably mounted within said body member operatively associatmovable within said body member in all directions in planes parallel to said work piece contacting surface, and countersink depth indicating means mounted upon said body member and operatively associated with said contact member.

3. A countersink depth gauge comprising es-, sentiaIly a tubular body member adapted to rest at one o f its ends against the work piece, a spherical contact member mounted within said body member at the w0rk piece contacting end thereof and freel movable in all directions therewithin, an indicator mechanism mounted upon the other end of said body member and having an indicator actuatihg element extending into said body member, and a plunger slidably mounted within said bod member operatively associated at its opposite ends with s'aid spherical contact member and said indicator actuating member, said contact mmber having aprotuberance therecn extending into a recess formed in a side wall portion of said body member.

4. A countersink depth gauge"comprising essentially a tubular body member adaptd to rest atone of its ends against the work piece; spherical contact member mounted within said body member at the Work piece 'contacting end therewithin, an indicator mechanism mounted upon the other end of said body member and.

having an indicator actuating element extending into said body member, and a plunger slidably mounted within saidbody member operatively associated at its opposite ends With said spherical contact member and said indicator actuating member, said contact memberhavng an integral elongated arm' portion extending through an opening through a side wali portion ofrsaid body member for preVenting total movement-of said contact member from within said body member and disassembly of the device. 1

5. A countersink depth gauge comprisingessentially a tubuiar body member adapted to rest at one of its ends againstthe work piece, a sph'er ical contact member mounted within said body member at the Work piece contacting end thereof and frely movablein all directionsthere within, an indicator mechanism mounted upon the other end .of said body member and having an indicator actuating element extending into said body member, and a plunger slidabiy mounted within said body member operatively associ ated at its opposite ends With said spherical contact member from said body member, said plunger being recessed intermediaceiy'of its ends to accommodate the inner end of a set screw extending through a side wall portion of said body member and providing at its ends stop means adapted to cooperate With said set screw for limiting movements of said plunger Within said body member.

6. A countersink depth gauge comprising essentially a tubular body member adapted to rest at one of its ends against the work piece, a spherical contact member mounted within said body member at the Work piece contacting end thereof and freely movab1e in all directions therewithin, an indicator mechanism mounted upon the other end of said body member and having an indicator actuating element extending into said body member, and a piunger slidabiy mounted within said body member operativeiy associated at its opposite ends With said spherica1 contact member and said indicatiar actuating member, said contact member having an integral elongated arm portion extending through an opening through a side wall portion of said body member for preventing total movement of said contact member from within said body member and disassembly of the device, said body member being provided With a second opening through a side wall portion thereof at 2 position substantially opposite to that of said first mentioned opening.

ARTHR A. SCHWARTZ. 

